Apparatus for producing smoke screens



June 10, 1947.- H. A. LEVEY ETAL.

APPARATUS FOR PRODUCING SMOKE SCREENS Filed May 4, 1942 lanzoalgaiierson,

,. Ha ro Leve Patented June 10, `1947 APPARATUS FOR PRODUOING.` SMOKESCREENS Harold A.VLevey and Alonzo C. Patterson, New` rleans, La.;Patterson said Levey assigner to said Application May 4, 1942, serialNo. 441,724

The present invention relates to a method and apparatus for producingsmoke screens or the like. More particularly the present inventionrelates to a smoke producer which is particularly adapted for use withan internal combustion engine, Diesel engine or other type of enginewherein substantial heat and substantial quantities of exhaust gases arenormally produced.

The apparatus of the present invention is particularlydesigned for usewith an ordinary in-` ternal combustion engine such as that incorporatedin a vehicle or boat, and is particularly capable of effiicentlyproducing in conjunction with the exhaust gases thereof a large volumeof dense smoke which is capable of screening the movef ments of men orequipment and of stationary or moving objects.

One ofthe objects of the present invention is the provision of a novelapparatus which utilizes a substantial proportion of the sensible heatof the exhaust gases flowing froman internal combustion engine, Dieselengine, or the like -to Vaporize and/o1- atomize a smoke producingcornposition.

A second object of the present invention is the provision of anapparatus includinglstorage tanks so connected to the exhaust manifoldof an engine that substantially all of the heat of the exhaust gases isutilized in vaporizing the fluid fed from the tanks. i

A third object of the present invention is the provision of a pumpadapted to 'be driven from a moving portion of an internal :combustionengine to Supply compressed air for feeding a suitable fluid into theexhaust manifold of an engine for vaporizing the same in order toproduce a dense volume of Smoke:

A fourth object of the present invention is to provide means to conservethe heat of `exhaust gases and utilize the heat thereof for vaporizingvarious types of smoke producing compositions.

A fifth object of the present invention is to provide a novel processfor the production of a dense smoke which comprises flowing high tem-`perature relatively inert gases in a heat insulated path, feeding asmoke producing composition to said gases, and thoroughly mixing thesame while imparting the heat of said gases to the composition tothoroughly volatilize and/or atomize the composition.

A sixth object of the present invention is to provide a novel processwhich comprises flowing high temperaturev relatively inert gas in a heatinsulated path, feeding smoke producing com- .4 claims. (c1. e- 359)position to the gases,and passing both the gases 15o and the compositionto successive turbulent and high temperature zones to thoroughly mix thegases with the smoke composition and thoroughly volatilize the smokecomposition. I

Other objects and advantages of lthe invention will be apparent from thesubsequent description and gures of the drawing, wherein: ,1

Figure 1 is a partly diagrammatic view of an apparatus according to thepresent invention;

Figure 2 is a section of` an Aexhaust, manifold and exhaust pipe showingthe disposition of the fedeing valves according to the present invention; I

Figure 3 is a section ofa diaphragm pump; n

Figure 4 is a section taken on the line 4-4 of Fig. 2; and ,Y

Figure 5 is a detail of a modified form of feeding orifice or jet.

Referringl to the figures of the drawing, and. particularly Fig. 1thereof, an internal combustion engine is indicated in general at Illandincludes an exhaust manifold II, provided with the usual exhaust portsindicated in dotted lines at I2. Connected to the exhaust manifold inany suitable manner is an exhaust pipe s I3. The exhaust manifold4 IIandthe exhaust pipe I3 is preferably insulated in order to conserve theheat of the gases passing therethrough, this insulation being indicatedat I4 and I5. Obviously, any suitable insulation capable of withstandingtemperatures in the neighborhood of 600 to 700 F. is suitable, such asasbestos,`magnesium oxide, or magnesium carbonate, and it is to beunderstood that this insulation maybe housed in a suitable housing orutilized in the form of premolded Sections.

As shown in Fig. 2, a needle valve structure indicated in general at I6is threaded into one end of the exhaust manifold. This needle valveincludes a suitable valve stem I'I and adjusting screw I8. The valvestem I'l is provided with the usual conical Shaped end and the valvecasing with the usual seat. As shown, the needle valve Structure l5feeds into the exhaust manifold at the very beginning thereof. Thispositioning of the needle valve is preferable, Since it is desirable inmost instances that the smoke producing composition be fedinto theexhaust manifold ahead of any of the ports so that the full heat of theexhaust gases Will -be utilized.

A Second needle valvestructure is indicated in general at I9, and ispositioned at the outlet of the exhaust manifold so that additionalsmoke` producing composition may be fedeL at this point. The needlevalve structure I9 also includes a1 suitable valve stem 20- and anadjusting screw 2|. It will be noted that the outlet of this secondneedle valve projects into the exhaust pipe at an angle of approximately45. It is important that the outlet of this second valve so projectsthat the outlet will be subjected to the sweeping action ofthe exhaustgases, and considerable turbulence will be created. Since the heat ofthe gases is somewhat less at this point, it is important that acomplete atomization of the fluid fed into the exhaust pipe take placeat this point and the angular positioning oi the outlet o the needlevalve |9 produces this effect. This outlet is indicated at 22. It willbe noted that the outlet projects into the casing in this valvestructure, as indicated at 23, and this projection insures the heatingof the outlet, inasmuch as it is surrounded by flowing hot gases.

Referring once again to Fig. 1, it will be noted that the needle valvesI6 and |9 are fed with fluid through the conduits 24 and 25. The conduit24 communicates with the bottom of a tank 2'6. Interposed in the conduit24 is a valve 21 which, in conjunction with the needle valve I6 servesto control the flow of fluid through the conduit 24 into the exhaustmanifold. The conduit 25 similarly opens into theA bottom of a tank 28and a valve 29 is interposed in the conduit 25 to regulate the nowtherethrough. The tanks 26 and 28 are each adapted to contain a suitablesmoke producing composition. This composition may be made from alubricating oil carrying in suspension inorganic salts which volatilizeat relatively low temperatures. Preferably also the com-positioncontains a viscosity increasing agent such as suitable metallic soapsexemplified by sodium stearate, calcium palmitate, etc. A more completedisclosure of the particular compositions which may be used will befound in copending application, Serial No'. 441,550, filed May 2, 1942.The same composition' may be also used in tank 28 or some othercomposition. Thus the type of equipment described is capable ofeffectively utilizing two different compositions of smoke formingproducts with different Vaporizing properties. If the screen formingcomposition requires elevated temperatures of highvalues in order tovaporize them, such a composition would preferably be admitted throughneedle valve |26 and stored in the tank 2G. On the other hand', if acompositionV requires less heat for its vaporization, it' would then bepreferable to admit' it through the needle valve and nozzle I9, and to'store the composition in the tank 28. It is` to be noted that thetemperatures in the manifold itself, if an ordinary internal combustionengine is used, would run between 500 to 600 F., and the temperatures atthe point of outlet of the needle valve |9 would run between 300 and 400F.

It is to be noted that the apparatus shown permits the utilization forthe development of smoke screens of two different types of composition,as well as permitting the addition of successive increments of the samecomposition at different points. By So providing different points ofadmission, complete vaporization of the first composition prior to thesecond addition is effected. This phenomena is more completelydiscussed, disclosed and claimed in the copending application of HaroldA. Leve-y, Serial No. 441,989, filed May 6, 1942, now Patent No.2,408,429, issued October 1, 1946.

The feed of' liquid from the tanks 26 and 28 is effected under theinfluence' of compressed a-i-r which is supplied to the tanks 26 and 28through the conduits 30 and 3|. Valves 32 and 33v are provided to varythe amount of compressed air fed. The two conduits 39 and 3| areconnected to the outlet of a diaphragm type pump indicated in general at34. As shown in Fig. 3, this pump includes a main chamber 35 covered bya leather diaphragm 36 and a ilexible metal diaphragm 3l. As thecomposite diaphragm structure is flexed inwardly and outwardly, airwithin the chamber 35 is compressed. Ball valves 38 and 39 are alsoprovided which produce a flow of air out of the chamber 35 in thedirection as indicated bythe arrow 49. The metal diaphragm 31 is movedinwardly and outwardly by rocker arm 4|. As shown in Fig. l, the rockerarm 4| is pivoted at 42 on the engine block and rests on a push rod 43at one end. A cam 44 reciprocates the push rod, said cam being rotatablewith a suitable shaft 45 which may be driven from the engine crank shaftor any other moving portion of the engine |0. A spring 46 is alsoprovided to move the rocker arm 4| back after the cam 44 and push rod 43have moved the same in one direction.

As shown in Figs. 2 and 4, a straight portion of the exhaust pipe I3 isprovided with projecting pins 41 which form a network through which thesmoke composition is vented. These pins or network are made of metal orother heat conducting sub-stance, and serve to transmit the heat of theexhaust pipe to the smoke screen mixture flowing through the interior ofthe pipe. It is to be understood that in place of the metal pins, ns orplates of metal may be fastened on the interior of the pipe in order toa'dmix and heat the gases owing therethrough. It is to be noted furtherthat this section of pipe is insulated, as indicated at i5 in order toconserve the heat therein. The outlet of the exhaust pipe is flared, asshown at 48, and an interior cone is provided, as indicated at 49 inorder to form an outlet capable of distributing the smoke over` thewidest possible area. In place of the flared orice shown, a series ofconcentric rings or tunnels may be used to more evenly distribute thesmoke formed.

Referring to Fig. 5, there is here shown a modifled orifice which isadaptedto be substituted at the outlet of the needle valve I9 and toproject substantially into the exhaust pipe. This outlet is formed of asuitable length of relatively small pipe indicated at 50, having aconical or pointed end indicated at 5|. found to be particularlyadvantageous where large engines discharging considerable volumes ofgases are used. It will also be noted that the nozzle or outlet in thismodication is provided with a spring member 54 which extends the fulllength of the nozzle. This spring member is so mounted that it may bereciprocated along the axis of the nozzle or even removed therefromvfrom the exterior of the apparatus. This enables the nozzle to becleaned out if it becomes clogged with deposit material from the smokecomposition. A similar spring member may be provided for the outlet ofthe needle valve I6 as well as the needle valve I9.

It will be noted further that by utilizing the diaphragm type pump ofthe character described, a constant air pressure is maintain-edr in thetanks of a relatively low order, as for example, four to ve pounds, thispressure being indicated by the respective gauges 52 and 53. This is dueto the strength of the spring 46 which moves the rocker arm 4| back.Obviously', this spring can be strengthened or weakened so that anydesired This type of outlet has been l maximum air pressure will besupplied to the tanks. It is important that this air pressure be limitedsince if this pressure were very large, there would be some danger ofthe smoke producing composition being sprayed through the needle valvei6 at too great a velocity so as to. prevent complete vaporization, andsome possibility of some of the smoke producing compositionbeingintroduced int-o the exhaust ports. It has been found in actualpractice, however, that even though the smoke producing composition isfed at the beginning of the exhaust manifold, none of this compositionfinds its way into the exhaust ports. By feeding the smoke producingcomposin tion through the needle valve IB into the exhaust manifold at apoint before the opening of the exhaust ports, a, very completevaporization and development of a mist of ner particle size coinpletelydispersed in the exhaust gases is produced due to the turbulenceresulting from the passage of the mixture past the open faces ofsuccessive exhaust ports. This phenomenon is particularly advantageouswhen the composition includes a hydrocarbon oil which requires aconsiderable amount of heat and turbulence for complete atomization. Inother words, there is here disclosed a process for the production of adense smoke which includes not only the mixing or introduction of thesmoke producing composition into high temperature inert gases, but alsoincludes the subsequent passage of such a mixture past successive zonesof high turbulence and relatively high heat.

What is claimed is:

1. In a smoke producer in combination, an internal combustion enginehaving an exhaust manifold, exhaust ports opening into said manifold, anexhaust pipe leading from said exhaust manifold, means opening into saidexhaust manifold in front of the exhaust ports to feed a smoke producingcomposition thereto, and a second means opening into said exhaust pipebeyond said manifold to feed smoke producing composition thereto, saidsecond means having an outlet positioned at an angle to the now of gasesin said exhaust pipe so that said gases will sweep smoke producing fluidfrom said outlet.

2. In a smoke producer in combination, an internal combustion enginehaving an exhaust manifold, exhaust ports opening into said manifold, anexhaust pipe leading from said exhaust manifold, means opening into saidexhaust man.. ifold in front of the exhaust ports to feed a smokeproducing composition thereto, a second means opening into said exhaustpipe beyond said manifold to feed smoke producing composition thereto,said second means having an outlet positioned at an angle to the flow ofgases in said exhaust pipe so that said gases will sweep smoke producingfluid from said outlet, and means in a portion of said exhaust pipe toconduct heat from the exhaust pipe to the gaseous mixture flowingtherethrough.

3. In a smoke producer in combination, an internal combustion enginehaving an exhaust manifold, exhaust ports opening into said manifold, anexhaust pipe leading from said exhaust manifold, means opening into saidexhaust manifold in front of the exhaust ports to feed a smoke producingcomposition thereto, a second means opening into said exhaust pipebeyond said manifold to feed smoke producing composition thereto, saidsecond means having an outlet positioned at an angle to the fiow ofgases in said exhaust pipe so that said gases Will sweep smoke producinguid from said outlet, and projecting pins in a portion of said exhaustpipe to conduct heat from the exhaust pipe to the gaseous mixtureflowing therethrough.

4. In a smoke producer in combination, an internal combustion enginehaving an exhaust manifold, exhaust ports opening into said manifold, anexhaust pipe leading from said exhaust manifold, means opening into saidexhaust manifold in front of the exhaust ports to feed a smoke producingcomposition thereto, a second means opening into said exhaust pipebeyond said manifold to feed smoke producing composition thereto, saidsecond means having an outlet positioned at an angle to the flow ofgases in said exhaust pipe so that said gases will sweep smoke producingfluid from said outlet, the outlet end of said exhaust pipe being flaredoutwardly and forming an outer cone, and an inner cone Within and spacedfrom said outer cone.

HAROLD A. LEVEY. ALONZO C. PATTERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,514,106 Savage Nov. 4, 19241,972,600 Reboul Sept. 4, 1934 2,173,756 Kronenberg Sept. 19, 19392,045,865 Morey June 30, 1936 2,070,038 Batt Feb. 9, 1937

